Pomegranates, originally cultivated in Iran and a valuable medicinal and nutritional fruit, could be converted into pomegranate juice powder to be accessible in other seasons and used as a valuable ...ingredient in other food and pharmaceutical products. In this research, pomegranate juice was spray dried at three maltodextrin levels (25, 35 and 45% w/w) and two inlet air temperatures (124 and 143°C) and physicochemical and nutritional characteristics of the powder were surveyed. The experiments were carried out to measure drying yield, water solubility index, apparent density, color values, anthocyanin content, and morphological properties of the pomegranate juice powders. Inlet air temperature just could affect density of the powder while maltodextrin level could influence anthocyanin content of the final powder as well. Higher maltodextrin levels and temperatures lowered a* values of the powder, due to the lower anthocyanin content remained in the product at these situations. SEM analysis revealed that lower maltodextrin levels and higher inlet air temperatures resulted in smaller but smoother particles. In conclusion, pomegranate juice powders produced at 25% maltodextrin level and 124°C, with high water solubility index of 95%, high density of 0.889gcm−3, and anthocyanin content of 8mgL−1, are suitable and nutritionally-rich choices for industrial production.
SEM analysis of pomegranate juice powder.
(45% maltodextrin and inlet air temperature of 143°C). Display omitted
•Pomegranate juice was spray dried at different maltodextrin levels and inlet air temperatures.•Inlet air temperature could just affect density of the powder.•Maltodextrin level could influence anthocyanin content of the final powder.•SEM revealed that lower maltodextrin resulted in smaller but smoother particles.
Drying is a complex process frequent in most of the food processing industries. The functional properties of food components, highly affected by the drying processes, significantly influence the ...scope of their application and commercial value. Food biopolymers such as proteins, carbohydrates, and mixed flours are important due to their functional properties including water solubility, swelling index, water/oil holding capacity, porosity, emulsification, foaming, bulk density, viscosity and gel properties.
This review study goes over the relationship between miscellaneous drying treatments applied on food biopolymers in research works carried out during the last two decades. It not only outlines the effect of drying/heating treatments on diverse biopolymers, but also compares the effect of each one (oven, sun, shade, solar, tray/cabinet, vacuum, freeze, fluidized bed, drum, and spray drying) on macromolecules of food products with each other, and monitors microstructural changes brought about by those methods. Finally, it summarizes the influence of novel dehydration techniques (assisted by microwave, ultrasound, infrared, vacuum impregnation, and phosphorylation through dry heating) being applied these days for the successful drying of food products to give a direction to experts following this topic in oncoming years.
Our comparisons show that among conventional drying approaches for processing of protein resources, freeze drying could be more efficient than other methods while spray drying might have similar or better performance. High drying temperatures decrease the swelling capacity of carbohydrates and increase their susceptibility to breakdown during hydrothermal processes. For drying of carbohydrate sources, fluidized bed, especially at low temperatures, oven and freeze drying could yield final powders with higher functional qualities. Foam-mat, sun and freeze drying could yield better final functional properties of dried flours than oven, solar, cabinet/tray and hot air drying approaches. With microwave drying, functional properties, as opposed to nutritional qualities, could be maintained more effectively than other drying techniques, e.g. freeze drying. While application of infrared, as a novel dehydration technique, might not improve functional properties of food powders in comparison with other superior drying techniques, vacuum impregnation, another novel drying approach, could result in high saving of functional ingredients in food powders, higher anthocyanin content and better antioxidant properties of the final product.
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•Functional properties of food biopolymers are highly affected by drying process, dryer type, temperature and, process time.•The best conditions for maintaining functional properties are a compromise between drying time and temperature.•Among drying methods, spray drying shows the appropriate conditions considering functional properties of food biopolymers.•Foam-mat, sun and freeze drying could represent better functional properties of dried flours than other drying methods.
In recent years, the problem of vitamin D deficiency has been echoed by extensive researches. Nutritionists believe that fortification of food products through this micronutrient is the best approach ...to solve this problem. In this study, properties of yogurt powders fortified with nano-liposomal encapsulated vitamin D were evaluated. The Taguchi method was deployed to design the treatments (16 runs) with 5 independent variables including temperature (160–190 °C), milk protein concentrate (0–3%
w
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), modified starch content (0–3%
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), gum Arabic (0–3%
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) and maltodextrin (10–25%
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), each at 4 levels. Dependent variables comprised of moisture content, solubility, colour and production (drying) yield. Analysis of our data revealed that the contribution order of different independent variables on responses was as follows: milk protein concentrate (30%), modified starch (28%), maltodextrin (22%), temperature (17%) and gum Arabic (3%). The average particle size of nano-liposomes containing vitamin D was about 120 nm. Also, SEM micrographs showed that addition of maltodextrin caused spherical powder particles with an even distribution in the matrix including yogurt and drying aids while incorporating milk protein concentrate, gum Arabic and modified starch brought about shrinkage as well as unevenness in the shape and size of powder particles.
Our aim was to evaluate the qualitative properties of kiwifruits produced by refractance window (RW) as a novel drying method. The effects of slice thicknesses (0.8, 1.6 and 2.4 mm) and drying ...temperatures (80, 90 and 100C) on drying duration as well as qualitative parameters of dried samples including textural hardness, color, rehydration index and organoleptic properties were investigated. The required time to reach the final moisture content was considerably lower in RW method compared with oven drying, which was maximally 140 min lower for slice thickness of 2.4 mm at 100C. Generally, ΔE values and rehydration ratios of oven‐dried kiwifruits were higher and lower than RW‐dried samples, respectively. The average scores given to each sensory property of oven‐dried samples were between 1 and 3, whereas they were in the range of 4–5 for RW‐dried kiwifruits, exhibiting more satisfactory situations for the latter samples.
Practical Applications
It is necessary to develop alternative drying methods that could guarantee quality retention and maximize financial productivity during the drying process. Refractance window is a novel drying technique utilizing circulating hot water to transfer thermal energy to a thinly spread liquid material placed on a conveyor belt. In this work, we have successfully utilized this technique for drying kiwifruits, and the results have been compared with conventional oven drying for the first time.
Soft cheeses are coagulated milk products obtained through acidification or applying a combination of acids and heat. In this research, in order to improve technological characteristics, the effects ...of different coagulants (salt and acids) and process parameters (temperature and homogenization pressure) on the organoleptic, textural, and functional characteristics of soft (unripened) cheese were investigated. The results revealed significant differences between cheeses coagulated with acid and mineral salt regarding protein recovery, fat content, and moisture content (
< .05). Acidic coagulants (74%-94%) resulted in higher cheese yield compared to mineral salt (66%-88%). Texture analysis indicated that the cheese produced with acetic acid had a firmer texture, while samples treated with citric acid exhibited better cohesiveness. Cheeses produced with minerals displayed more acceptable organoleptic characteristics regarding flavor, odor, and texture. This study offers valuable technological insights into cheese production with the highest yield and maximum acceptability.
In this research, effect of Refractance Window (RW) drying on the quality properties of the kiwifruit samples was investigated. Drying temperatures of 80–100 °C, slice thickness of 0.8–2.4 mm and ...Mylar thickness of 100–300 µm were the independent variables and different qualitative attributes including drying duration, textural hardness, colour, rehydration ratio and organoleptic properties were responses monitored in each situation. Drying temperature was the most important factor contributed to quality features of RW dried kiwifruits with significant effects on all properties. Similarly, slice thickness influenced nearly all quality traits except textural hardness and some colour indices. However, Mylar membrane thickness failed to affect about every qualitative property of kiwifruit samples significantly. The majority of organoleptic properties of RW dried kiwifruits, including flavour, colour, texture, shrinkage and overall acceptance, were judged to be in the range of medium to good quality (scores of 3–4) by panellists.
Encapsulation of fatty acids/fish oils within complexes could overcome low water solubility and oxidation susceptibility of these essential oils when considering their incorporation into food ...products; besides, it can mask their undesirable flavour and odour. So, in this research, nanoencapsulation of omega-3 (ω3) fatty acids by gelatin-gum Arabic complexes was optimized through response surface methodology (RSM). The effects of three independent variables including gelatin concentration (33–66%), ω3 concentration (10–30%), and homogenization speed (10,000–20,000 rpm), on different responses i.e. particle size, moisture content, colour values, free oil, encapsulated oil, and encapsulation efficiency were determined. It was revealed that homogenization speed had the highest impact on particle size; at 10,000 rpm, the smallest nanocapsules with (26–114 nm) were produced. Moisture content of dried nanocapsules was between 4.2 and 7.3%, and gelatin concentration was the most important factor. Similarly, colour values were mostly affected by gelatin concentration and increasing gelatin ratio lowered L values and raised b values of powders. Encapsulation efficiency of powder particles was between 69.74 and 98.41%, and homogenization speed had the highest effect on this response (P < 0.01). SEM graphs revealed that the nanocapsules had rather smooth and fragile surfaces, with some porous structures.
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•The soluble complexation, caused suitable nanoscale carriers for fish oil.•The optimum gelatin-GA complexation led to the highest encapsulation efficiency.•Nanocapsules having ω3 fatty acids could be produced successfully to enrich food products.
•Natural anthocyanins were used for spray drying encapsulation.•RSM was applied for optimization of microencapsulation efficiency.•Physical properties of encapsulated powders were ...investigated.•Samples produced with MD+GA had highest efficiency and best powder quality.•Optimum conditions were 24.54% wall material and 13.82% anthocyanin load.
The barberry (Berberis vulgaris) extract which is a rich source of anthocyanins was used for spray drying encapsulation with three different wall materials, i.e., combination of maltodextrin and gum Arabic (MD+GA), maltodextrin and gelatin (MD+GE), and maltodextrin (MD). Response Surface Methodology (RSM) was applied for optimization of microencapsulation efficiency and physical properties of encapsulated powders considering wall material type as well as different ratios of core to wall materials as independent variables. Physical characteristics of spray-dried powders were investigated by further analyses of moisture content, hygroscopicity, degree of caking, solubility, bulk and absolute density, porosity, flowability and microstructural evaluation of encapsulated powders. Our results indicated that samples produced with MD+GA as wall materials represented the highest process efficiency and best powder quality; the optimum conditions of microencapsulation process for barberry anthocyanins were found to be the wall material content and anthocyanin load of 24.54% and 13.82%, respectively. Under such conditions, the microencapsulation efficiency (ME) of anthocyanins could be as high as 92.83%.
In this study, spray-drying technique was used to develop Persian gum-based microcapsules having cinnamon essential oil (CEO) where, using a simple centroid mixture design, the proportion of ...maltodextrin to Persian gum was optimized. The response factors which were optimized included powder recovery, encapsulation efficiency, and the release of CEO. Based on the formulation optimization, 8.25% maltodextrin and 1.74% Persian gum were required to achieve the optimum microcapsules having the highest powder recovery, encapsulation efficiency and CEO release. The evaluation of the optimum microcapsules was carried out based on particle size, moisture content, solubility, in vitro release, antioxidant activity, Fourier transform infrared spectra (FTIR), differential scanning calorimetry (DSC), and chemical compositions through Gas Chromatography-Mass Spectrometry (GC-MS). Physical interaction between CEO and the wall materials was proved by the results of FTIR. Enhanced water solubility of the CEO and guarding impact on antioxidant activity were observed in the optimum microcapsules. The pattern of the release of encapsulated CEO from simulated saliva is best described as the Fickian diffusion mechanism where immediate release (80%) of the encapsulated CEO was observed. Based on the findings of this study, efficient and novel carriers for the encapsulation of essential oils could be developed through Persian gum microcapsules.
•Encapsulation efficiency of higher than 78% was obtained for Cinnamon essential oil (CEO) microcapsules.•Suitability of Persian gum as encapsulating agent for the development of CEO capsules.•Proportion of maltodextrin and Persian gum impacted characteristics of the developed capsules.•Burst release (80%) of the encapsulated CEO from its capsules in the oral phase.
A common problem of electrospinning of plant proteins is that these kinds of proteins, including soy protein isolate (SPI), should be highly soluble and preferably in a random coil structure rather ...than the globular conformation. The current solution is to apply thermal treatment; however, it results in extensive organoleptic consequences (e.g. color degradation and off-flavor) and loss of nutrients. Thus, if a non-thermal technology such as high hydrostatic pressure (HHP) increases the disordered structure of the protein, it could facilitate the electrospinning of the protein and eliminate the barriers of thermal treatment, forming our hypothesis in this research. To this end, initially, extensive experiments including protein solubility, sulfhydryl content, turbidity, surface hydrophobicity, circular dichroism, and viscosity tests were carried out on HHP (200, 400 and 600 MPa) and thermally treated SPI samples (3.5% and 7% w/w). The results of sulfhydryl content revealed that disulfide bonds decreased at 400 MPa more intensely than other pressures while surface hydrophobic forces were promoted at this pressure. The circular dichroism test results showed that HHP treatment resulted in higher disordered structures and lower ordered ones, which is particularly helpful for the electrospinning process; besides, lower β-sheet content achieved by HHP treatment is especially useful for attaining defect-free fibers. For the first time, in this research, ideal electrospun fibers with average diameters of 300–400 nm were achieved through HHP processing, without using any thermal energy.
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•Efficiency of HHP denaturation on SPI was compared with thermal denaturation.•Structural properties of SPI denatured by HHP were studied extensively.•HHP denaturation at 400 MPa resembled thermal denaturation of SPI sufficiently.•For the first time, HHP denaturation of SPI was followed by its electrospinning.
